Also (send finger was faster than typing finger), that ICMP data signature is typical of Nachi. Whomever is sending it is infected... Jim Harrison MCP(NT4, W2K), A+, Network+, PCG http://www.microsoft.com/isaserver http://isaserver.org/Jim_Harrison http://isatools.org Read the help, books and articles! ----- Original Message ----- From: "Eric Poole" <EPoole@xxxxxxxxxxxxxxxxxxxx> To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> Sent: Wednesday, January 14, 2004 10:32 Subject: [isalist] ISA Server detected a spoof attack http://www.ISAserver.org I'm getting these about every half hour from our internal Cisco Works box (172.16.10.168). The 2.9 address is the ISA external NIC that is routed through our PIX. Any ideas? "ISA Server detected a spoof attack from Internet Protocol (IP) address 172.16.10.168. A spoof attack occurs when an IP address that is not reachable via the interface on which the packet was received. If logging for dropped packets is set, you can view details in the packet filter log." Here's a sample from the packet filter log. "1/13/2004, 20:43:17, 172.16.10.168, 172.16.2.9, ICMP, 8, 0, -, BLOCKED, 172.16.2.9, 45 00 00 3c 20 74 00 00 7f 01 b6 7b ac 10 0a a8 ac 10 02 09, 08 00 a1 b6 04 00 77 6e ad ad ad ad ad ad ad ad ad ..." _______________________________________________ Eric Poole IS Security Analyst Community Medical Centers 1140 "T" Street, Fresno, California 93721 559-459-6784 (phone) 559-459-2045 (fax) ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=isalist ISA Server Newsletter: http://www.isaserver.org/pages/newsletter.asp ISA Server FAQ: http://www.isaserver.org/pages/larticle.asp?type=FAQ ------------------------------------------------------ Other Internet Software Marketing Sites: Leading Network Software Directory: http://www.serverfiles.com No.1 Exchange Server Resource Site: http://www.msexchange.org Windows Security Resource Site: http://www.windowsecurity.com/ Network Security Library: http://www.secinf.net/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jim@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub')